Is Sentinel of the Nameless City legal in Standard, Modern, and Commander?

Sentinel of the Nameless City is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Sentinel of the Nameless City

Q: What type of card is Sentinel of the Nameless City?

Sentinel of the Nameless City is a Creature — Merfolk Warrior Scout. Its oracle text reads: "Vigilance Whenever this creature enters or attacks, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")"

Creature — Merfolk Warrior Scout

Vigilance

Whenever this creature enters or attacks, create a Map token. (It's an artifact with ", , Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")